The specificity of amylin for the diagnosis of pancreatic adenocarcinoma

Background. Diabetes mellitus or impaired glucose tolerance occurs in up to 80% of patients with pancreatic cancer at the time of cancer diagnosis. It has been reported that plasma amylin (islet amyloid polypeptide [IAPP]) levels are elevated in all patients with pancreatic cancer who are diabetic, and even moderately elevated in pancreatic cancer patients with normal glucose tolerance. Aim. To determine the specificity of elevated amylin levels for pancreatic cancer. Methods. Plasma amylin levels were determined in 168 patients with one or more of the following medical conditions: benign and malignant biliary obstruction, pancreatic cancer, chronic pancreatitis, acute pancreatitis, other gastrointestinal (GI) malignancies, and newly diagnosed type II diabetes. Results. Elevated levels of plasma amylin were detected in several disorders other than pancreatic cancer - particularly chronic pancreatitis, other GI malignancies, and biliary obstruction from benign causes. No statistical differences in amylin levels were detected for any of the tested medical conditions when compared to pancreatic adenocarcinoma. Conclusion. These results suggest that elevated plasma amylin is not specific for pancreatic cancer, thereby limiting its role as a tumor marker. Further studies are needed to determine whether amylin, if used in conjunction with other biological markers, could be useful for the diagnosis of pancreatic cancer.